Conventionally, as a method of predicting the wear of a tire such as a pneumatic tire used in automobiles and so forth, in Japanese Patent No. 3,277,155 for example, there is disclosed a technology that measures the amount of wear and the frictional energy of a tire and predicts the wear of the tire with a rubber index that is determined on the basis of these.
Further, as a device that measures frictional energy, in Japanese Patent No. 3,277,155 and Japanese Patent No. 3,406,643 for example, there are disclosed contact portion measuring devices for tire contact patches that apply a marking to a tire, image the tire contact patch with a camera, measure the shear force and the slippage of the tire contact patch on the basis of the image, and measure the frictional energy.
Further, in Japanese Patent No. 3,277,155 and Japanese Patent Application Laid-Open (JP-A) No. 2006-242697, there are disclosed Lambourne testing devices that measure, with the so-called Lambourne test, the wear of a sample (test piece) of rubber used in a tread portion of a tire.
Further, in JP-A No. 2003-50190, there is disclosed a device that measures the amount of wear of a tire with a drum wear test.